The fossil land and freshwater snails of Oggenhausen (Middle Miocene, Germany)

Abstract

The Middle Miocene fossil site of Oggenhausen in southern Germany was first described in the 1920‘s, with reports of nine gastropod species. Much later, in the 2000‘s, a second and coeval site was described, named Oggenhausen 2 and counting with eight gastropod species, all of them distinct from the first site (hence named Oggenhausen 1). Here we present a revision of the historical material from Oggenhausen 1 alongside new material from Oggenhausen 2. After the revision, six species are known from Oggenhausen 1 (the records of Triptychia kleini and Gastrocopta acuminata could not be confirmed) and 13 from Oggenhausen 2. The following are new records for Oggenhausen 2: Lymnaea cf. dilatata, Gyraulus applanatus, Megalotachea silvana, Palaeotachea renevieri, Granaria sp., Gastrocopta acuminata and ?Truncatellina sp. Oggenhausen 2 is interpreted as a shallow lake or an oxbow lake, formed by the river that deposited the layers of Oggenhausen 1. The freshwater snails are consistent with slow-flowing or stagnant waters, while the terrestrial species indicate that the area surrounding the lake was covered by humid vegetation.